浆膜腔积液转移性肺腺癌细胞中TTF-1的表达

目的 探讨甲状腺转录因子-1(TTF-1)在浆膜腔积液肺腺癌细胞中的表达，为肺腺癌的诊断和鉴别诊断提供新的依据。方法 选用浆膜腔积液转移性腺癌共60例(胸水40例，腹水17例，心包积液3例)。经组织学或结合临床资料证实的肺腺癌36例，泌尿生殖道腺癌14例，胃肠道腺癌8例，乳腺癌2例。每例均制备HE染色的涂片和离心沉渣经琼脂和石蜡包埋而成的细胞块，并用细胞块切片作TTF-1免疫细胞化学染色。结果 36例肺腺癌中有26例表达TTF-1，24例肺外腺癌中只有2例表达TTF-1，其敏感性为72．2％，特异性为91．7％。结论 TTF-1在浆膜腔积液肺腺癌具有较高的敏感性和特异性，在排除甲状腺癌的可能性后，TTF-1阳性表达很大程度上提示腺癌原发于肺。     

浆膜腔积液细胞学诊断间皮瘤的临床病理学分析

目的探讨通过免疫细胞化学染色检测的几种标志物以及荧光原位杂交(FISH)检测CDKN2A基因缺失在浆膜腔积液间皮瘤诊断中的价值。方法收集2019—2022年14例发生于胸腔及腹腔弥漫性间皮瘤的浆膜腔积液细胞学标本及活检组织学标本, 应用免疫细胞/组织化学方法检测BRCA相关蛋白1(BAP1)和甲基硫腺苷磷酸化酶(MTAP), 以及FISH检测CDKN2A的缺失。同时14例均检测了常规用于间皮瘤鉴别诊断的抗体组合, 包括Calretinin、细胞角蛋白(CK)5/6、WT1、D2-40、上皮细胞膜抗原(EMA)、结蛋白、GLUT1。另收集20例良性间皮细胞反应性增生的浆膜腔积液作为阴性对照。结果免疫细胞/组织化学染色结果显示, 14例间皮瘤中9例显示BAP1蛋白表达缺失(9/14);5例MTAP表达缺失(5/14);12例表达EMA(12/14), 11例表达GLUT1(11/14);4例表达结蛋白(4/14), 其中3例为局灶阳性;Ki-67阳性指数5%～40%(平均为20%);FISH检测CDKN2A结果显示:1例(1/14)纯合性缺失, 6例(6/14)杂合性缺失, 7例(7/14...     

免疫组化标志物在鉴别浆膜腔积液恶性肿瘤细胞中的应用价值

目的探讨免疫组化标志物鉴别浆膜腔积液中恶性肿瘤来源及分类的临床价值。方法细胞学筛选恶性浆膜腔积液105例,分别采用常规细胞学涂片、薄层液基细胞技术制片、薄层液基细胞技术制片+常规细胞学涂片以及细胞蜡块切片结合免疫组化检测分析。结果对105例浆膜腔积液恶性肿瘤细胞来源及类型进行鉴别:胸水60例中腺癌58例,分别来源:肺42例、乳腺10例、卵巢4例及胃肠道2例;鳞癌1例;恶性间皮瘤1例。心包积液9例,均为腺癌,分别来源:肺6例,乳腺3例。腹水36例,其中腺癌35例,22例来源于卵巢,胃肠道12例,肺来源1例,弥漫大B细胞淋巴瘤1例。薄层液基细胞技术制片、薄层液基细胞技术制片+常规细胞学涂片以及细胞蜡块切片联合免疫组化检出率明显优于常规细胞学涂片(P0.05)。细胞蜡块切片联合免疫组化检测能准确鉴别浆膜腔积液中恶性肿瘤的来源及分类。结论常规细胞学涂片、薄层液基细胞技术制片、薄层液基细胞技术制片+常规细胞学涂片以及细胞蜡块切片结合免疫组化检测分析,在疑难恶性浆膜腔积液鉴别诊断及分类中具有重要的价值,值得临床推广应用。     

胸腔积液细胞学诊断恶性胃肠道间质瘤一例

胃肠道间质瘤(GIST)转移至浆膜腔者非常罕见。现就1例原发于胃的GIST且胸腔积液中查见GIST肿瘤细胞的病例进行分析, 观察患者胸腔积液涂片的细胞学形态、细胞块及相应组织学切片的形态特点, 总结GIST在浆膜腔积液中的细胞学诊断要点及鉴别诊断要点。     

细胞DNA定量分析在脱落细胞学诊断中的应用

目的 探讨自动细胞DNA定量分析系统在良恶性胸水、腹水、心包积液及乳腺包块诊断中的价值.方法 297例浆膜腔积液(胸水185例、腹水94例、心包积液18例),经细胞采集器处理,每例制成4张薄层细胞片,2张细胞片做巴氏染色,用于常规细胞学检查.另2张经Feulgen染色,用自动细胞DNA定量分析系统检测.122例乳腺包块住院患者,诊断医师进行针吸穿刺后每例制成2张薄层涂片,1张涂片做巴氏染色,用于常规细胞学检查.另1张经Feulgen染色,用自动细胞DNA定量分析系统检测.每例均有病理结果证实.结果 297例浆膜腔积液标本常规检测138例(44.5%)异常,而同样的标本中DNA定量检测131例(44.1%)异常.常规细胞学诊断为癌及可疑癌细胞84例中100%出现异倍体细胞,常规诊断为找到异型细胞的54中有47例(87%)出现异倍体细胞.122例乳腺肿物经病理证实,41例为乳腺良性肿瘤,81例为恶性.常规细胞学方法对良恶性乳腺包块的诊断阳性率分别为92.7%、91.4%,AICM的诊断阳性率分别为100%、90.1%.结论 应用自动细胞DNA定量分析系统可弥补常规形态学工作的不足,二者协同诊断,可发现早期癌变的细胞,提高诊断率,为临床制定治疗方案提供有价值的信息,使细胞学检查工作更完善、客观.     

浸润性乳腺癌术前FNA近似分子分型的临床意义

目的探讨浸润性乳腺癌术前细针吸取细胞学(fine needle aspiration,FNA)近似分子分型的可行性及临床意义。方法对42例女性原发性乳腺癌患者术前行细针穿刺术,涂片后进行细胞学诊断。利用免疫细胞化学技术检测ER、PR、HER2、CK5/6和EGFR表达情况,将乳腺癌近似分为腺腔A型(Luminal A)、腺腔B型(Luminal B)、纯HER2过表达型(pure HER2-overexpressing)、基底样型(basal-like)、HER2过表达基底样型(basal-HER2)及正常乳腺型(null)6个分子亚型。将其与术后对应标本的病理学及免疫组化结果进行比较。结果术前穿刺涂片诊断为"高度可疑乳腺癌"及"乳腺癌"的42例女性患者,经术后病理组织学证实均为浸润性乳腺癌,细胞学诊断准确率为100%。在42例乳腺癌细针吸取细胞涂片上利用免疫细胞化学进行术前各分子标记的检测,其中ER/PR阳性率为52.38%(22/42),HER2阳性率为42.86%(18/42),EGFR/CK5/6阳性率为19.04%(8/42)。相对应的石蜡切片经免疫组化检测,ER/PR阳性率分别为52.38%(22/42),HER2阳性率为40.48%(17/42),EGFR/CK5/6阳性率为23.81%(10/42)。其中,1例细胞涂片HER-2为阳性,而对应的石蜡切片为阴性;2例石蜡切片EGFR为阳性,而对应的细胞涂片为阴性,两种方法差异无统计学意义(P>0.05)。结论 FNA是术前诊断乳腺癌准确、易行的方法之一。浸润性乳腺癌术前FNA近似分子分型简单明了,切实可行。其有助于术前掌握乳腺癌的生物学特征,可能成为指导术前新辅助化疗、术式选择的有用指标。     

细胞块切片与常规细胞涂片免疫组化染色在胸腔积液病诊断中的价值

常规细胞涂片检测胸腔积液病敏感度相对较低(50%~78%),不能清晰鉴别浆膜腔原发性间皮性肿瘤与转移性癌,可能与两者细胞形态十分相似有关[1]。准确区分转移性癌与间皮性肿瘤可有助于临床医师选择精准、有效的治疗方式[2],近年细胞块切片免疫组化染色法越来越受到重视,其在鉴别间皮性肿瘤与转移性癌的敏感度较高,获得临床医师的青睐[3]。本文着重探讨胸腔积液病的细胞块切片与常规细胞涂片免疫组化染色的临床运用价值,现报道如下。     

LCT与ICC结合在胸腹水细胞学鉴别诊断中的应用

目的:探讨液基薄层细胞检测(LCT)技术与免疫细胞化学(ICC)技术在胸腹水细胞学鉴别诊断中的意义.方法:在87例胸腹水液基细胞涂片中应用免疫细胞化学技术检测癌胚抗原(CEA)、上皮细胞膜抗原(EMA)、间皮细胞(MC)抗体及波形蛋白(Vimentin)的表达并与HE染色比较.结果:腺癌中CEA、EMA、MC、Vimentin阳性表达率分别为88.2%、90.2%、5.9%和3.9%.增生性间皮细胞中CEA、EMA、MC、Vimentin阳性表达率分别为5.6%、2.8%、97.2%和88.9%.结论:免疫细胞化学技术可应用于胸腹水LCT涂片.选择一组特异的抗体(CEA、EMA、MC、Vimentin)并结合脱落细胞HE染色可以在转移性腺癌与增生性间皮细胞的鉴别诊断中起重要作用.     

数控标准化细胞块制备技术在子宫颈高级别鳞状上皮内病变中的筛查价值

<正>近年来细胞蜡块技术在传统的细胞学领域有着广泛的应用, 包括痰液、尿液、灌洗液、浆膜腔积液、脑脊液、妇科(子宫颈或子宫内膜脱落细胞)、穿刺液等标本。文献报道显示细胞蜡块技术利于样本长期保存, 与单纯细胞学涂片、制片相比更能明确诊断肿瘤的组织类型, 提高诊断正确率, 而且可拓展应用于免疫组织化学、分子病理等检测, 进一步提高疾病诊断效率[1]。子宫颈细胞块HE染色形态除具有细胞学特征外, 还表现出一定     

浆膜腔积液中的淋巴造血组织肿瘤细胞病理诊断分析

目的 探讨用细胞病理方法诊断浆膜腔积液中的淋巴造血组织肿瘤的可行性和准确性,避免漏诊和误诊,评估用细胞块切片进行免疫细胞化学染色的作用.方法 收集通过组织活检证实的伴发浆膜腔积液的淋巴造血组织肿瘤33例,对其临床特点、细胞形态、免疫表型特征等进行分析,另外1例结外鼻型NK/T细胞淋巴瘤进行EBER原位杂交检测,3例T淋巴母细胞白血病/淋巴瘤、2例弥漫性大B细胞淋巴瘤(DLBCL)和2例伯基特淋巴瘤进行了基因重排分析.结果 累及浆膜腔的33例淋巴造血组织肿瘤包括T淋巴母细胞白血病/淋巴瘤12例;成熟B细胞肿瘤16例,其中DLBCL 9例,伯基特淋巴瘤2例,浆细胞骨髓瘤2例,慢性淋巴细胞白血病/小B细胞淋巴瘤2例,套细胞淋巴瘤1例;成熟T细胞和NK细胞肿瘤3例,其中血管免疫母细胞性T细胞淋巴瘤、结外鼻型NK/T细胞淋巴瘤、T细胞幼淋巴细胞性白血病各1例;粒细胞肉瘤和肥大细胞肉瘤各1例.8例DLBCL、2例浆细胞骨髓瘤、慢性淋巴细胞白血病/小B细胞淋巴瘤、1例套细胞淋巴瘤、T淋巴母细胞白血病/淋巴瘤、血管免疫母细胞性T细胞淋巴瘤、肥大细胞肉瘤共16例为复发病例,其余17例均以浆膜腔积液为首发表现并由细胞病理初诊.所有病例细胞病理学诊断均与组织病理学诊断结果相符.结论 结合临床特点、细胞形态、免疫表型、原位杂交和基因重排等检测,用细胞病理方法可以对浆膜腔积液中的淋巴造血组织肿瘤,特别是复发病例进行明确诊断和鉴别诊断.     

Cellient™ automated cell block versus traditional cell block preparation: a comparison of morphologic features and immunohistochemical staining

Traditional cell block (TCB) sections serve as an important diagnostic adjunct to cytologic smears but are also used today as a reliable preparation for immunohistochemical (IHC) studies. There are many ways to prepare a cell block and the methods continue to be revised. In this study, we compare the TCB with the Cellient? automated cell block system. Thirty‐five cell blocks were obtained from 16 benign and 19 malignant nongynecologic cytology specimens at a large university teaching hospital and prepared according to TCB and Cellient protocols. Cell block sections from both methods were compared for possible differences in various morphologic features and immunohistochemical staining patterns. In the 16 benign cases, no significant morphologic differences were found between the TCB and Cellient cell block sections. For the 19 malignant cases, some noticeable differences in the nuclear chromatin and cellularity were identified, although statistical significance was not attained. Immunohistochemical or special stains were performed on 89% of the malignant cases (17/19). Inadequate cellularity precluded full evaluation in 23% of Cellient cell block IHC preparations (4/17). Of the malignant cases with adequate cellularity (13/17), the immunohistochemical staining patterns from the different methods were identical in 53% of cases. The traditional and Cellient cell block sections showed similar morphologic and immunohistochemical staining patterns. The only significant difference between the two methods concerned the lower overall cell block cellularity identified during immunohistochemical staining in the Cellient cell block sections. Diagn. Cytopathol. 2010. © 2010 Wiley‐Liss, Inc.     

Fine-needle aspiration: Comparison of smear,cytospin, and cell block preparations in diagnostic and cost effectiveness

We compared the results of smears to those of cytospin and cell block preparations from fine-needle aspirations to determine the cost effectiveness of each and to determine which should be routinely obtained. We reviewed 844 cases, 361 of which had both smears and cytospins, and 483 of which had both smears and cell blocks. Smears alone were diagnostic in 94% of cases (796/844 cases), cytospins alone diagnostic in 43% of cases (154/361 cases), and cell blocks alone diagnostic in 57% of cases (277/483 cases). Cytospins contributed additional information beyond that obtained from smears in 2% (7/361) and cell blocks in 12% (57/483) of cases. When smears were nondiagnostic, cytospins contributed additional information in 10% (2/21) of cases and cell blocks contributed additional information in 44% (12/27) of cases. The cost of providing a diagnosis from smear alone is $212, from cytospin alone is $352, and from cell block alone is $392. The cost for additional information established by cytospin is $7,736 and by cell block the cost is $1,906. Smears are superior to either cytospins or cell blocks in providing a diagnosis. It is not cost-effective to obtain either cytospins or cell blocks in addition to smears on all cases. However, it is cost-effective to obtain cell blocks when the immediate smear evaluation is nondiagnostic. Diagn. Cytopathol. 1998;19:70–74. © 1998 Wiley-Liss, Inc.     

Accuracy of fine needle aspiration biopsy processed by cytologic smear and cell block techniques for the diagnosis of lacrimal gland tumors: a study of 48 cases

Objective: To study the accuracy of fine needle aspiration biopsy (FNAB) processed by smear cytology and cell block (CB) techniques for the diagnosis of lacrimal gland tumors (LGTs). Study Design: In a prospective study, we enrolled 48 consecutive patients with LGTs. Immediately after excision of LGTs, the tissues were underwent FNAB with 23-gauge needles. The FNAB samples were processed to produce cytologic smears and CB from which slides were cut for immunohistochemical staining. The remainders were submitted for routine histopathologic processing. The diagnostic value of FNAB was assessed by comparing the FNAB diagnoses to those made by routine histopathology. Results: Cytopathologic evaluations based on smear cytology and CB with sections stained immunohistochemically can distinguish non-epithelial lesions from epithelial ones in all cases. The diagnostic sensitivities, specificities, and accuracies for distinguishing benign from malignant lesions were: cytologic smears--76%, 68%, and 71%, respectively; CB with immunohistochemical staining--88%, 87%, and 88%, respectively. The accuracy of the tissue diagnosis compared to routine histopathology was less for cytologic smears (58%) than for CB with immunohistochemistry (81%; P < 0.05). Conclusions: FNAB of LGT processed using a CB technique capable of producing immunohistochemically stained slides results in a greater percentage of accurate tissue diagnoses than do cytologic smears, when compared to routine histopathology.     

琼脂石蜡双包埋切片在胸水细胞学诊断中的应用

目的探讨胸水琼脂石蜡双包埋切片在肿瘤细胞学诊断中的意义。方法对44例胸水沉淀物分别进行常规涂片和琼脂石蜡双包埋切片,并对琼脂石蜡双包埋切片进行免疫组织化学染色。结果在确诊的21例恶性胸水中,琼脂石蜡双包埋切片法检测癌细胞的阳性率为90.48%,显著高于涂片法52.38%。11例涂片法阳性的标本中,只有5例做出了病理分类诊断,而19例琼脂石蜡双包埋切片阳性的标本均做出了病理分类诊断。琼脂石蜡双包埋切片的免疫组织化学染色阳性结果定位准确,图象背景清晰。结论琼脂石蜡双包埋切片细胞集中,可以提高恶性胸水癌细胞的检出率和做出分型的病理诊断,利于以及进行免疫组织化学检测。     

Toxoplasmosis in a post-transplant bronchoalveolar lavage: a case report

Toxoplasma gondii usually causes an asymptomatic and then latent infection in human adults; however, a potentially fatal disseminated form can occur in immunocompromised patients. Given that the diagnosis of acute Toxoplasma infection, as opposed to latent disease, relies on finding direct evidence of T. gondii infection in tissue, pathologic examination is critical. There have only been a few reports describing the cytomorphology of Toxoplasma in exfoliative cytology, and no reports of the findings in Thin Prep. In this report, we describe a fatal case of toxoplasmosis in a cardiac transplant patient that was diagnosed by respiratory cytopathology. Although the extracellular organisms were well visualized on the Wright-Giemsa stained cytospin, they were only faintly seen on the Pap-stained cytospin trapped within mucin and were not easily appreciated on the ThinPrep slides nor the H&E stained cell block sections. An immunohistochemical stain for Toxoplasma performed on the cell block was strongly positive, and an autopsy performed on the patient confirmed disseminated infection. Our case illustrates that the diagnosis of Toxoplasma in exfoliative cytology specimens can be challenging since organisms are not well visualized on ThinPrep or Pap-stained material; therefore, Wright-Giemsa stained material can be particularly helpful.     

Individual specimen triage of effusion samples: an improvement in the standard of practice, or a waste of resources?

The standard of practice in cytopathology does not include an individual specimen triage (IST) for sample optimization, but rather prescribes a uniform procedure, e.g., for smears, cell blocks, and cytospins. IST requires additional resources. We sought to evaluate whether IST would result in enhanced diagnostic accuracy and specimen turnaround time in effusions. In order to evaluate the efficacy of IST, 50 effusion samples (31 pleural, 16 peritoneal, and 3 pericardial), each with a minimum volume of 50 ml, were utilized. Each sample was prepared via IST to include at least two initial prepared Diff-Quik-stained cytospins on which the IST was based, as well as a standard cytopreparation protocol for nontriaged samples (NTS) which was limited to 3 smears (2 Papanicolaou-stained, and 1 Diff-Quik-stained) and a hematoxylin-eosin (H&E)-stained cell block section. All triaged and NTS were reviewed retrospectively to determine if IST offered any advantages over the standard cytopreparation protocol for effusion samples. Each was evaluated for diagnostic concordance, turnaround time for final diagnosis, and optimal preparation. In 46 cases, diagnoses in IST and NTS were 100% concordant. Four cases showed minor discrepancies between the original and the NTS diagnoses. In general, the discordant cases were due to sparse cellularity in a specimen composed largely of blood. There was no difference in turnaround time for final diagnosis. Based on a review of all samples, the combination of cell block preparation and cytospins (stained with Diff-Quik and Papanicolaou stains) were considered optimal for microscopic evaluation. IST offers no practical advantage over the NTS standard specimen preparation in relation to the accuracy of final diagnosis or turnaround time. The lysing of grossly bloody fluids with subsequent preparation of cytospins yielded superior preparations for microscopic evaluation over NTS. The standard preparation of effusion samples should include the preparation of a cell block, and cytospins stained with Diff-Quik and Papanicolaou stains, for optimal microscopic evaluation.     

The value of ThinPrep and cytospin preparation in pleural effusion cytological diagnosis of mesothelioma and adenocarcinoma

The diagnosis of malignant mesothelioma requires an integration of the clinical presentation, radiological studies, and immunohistochemical stain of histological sections. Cytological diagnosis on pleural effusions of mesothelioma and pulmonary adenocarcinoma is highly desirable but debatable. A spectrum of cytological features has been found to be associated more commonly with malignant mesothelioma (e.g., peripheral cytoplasmic skirt, bubbly cytoplasm, cyanophilic cytoplasm, and scalloped border of cell balls) vs. adenocarcinoma (e.g., two-cell population, inspissated cytoplasmic material, cytoplasmic vacuole, angulated and indented nuclei, and smooth border of cell balls) to only name a few. The current study is designed to assess whether the introduction of a liquid-based technology such as ThinPrep (TP) can provide additional diagnostic value in addition to the conventional cytospin Diff-Quik (DQ) preparations. Pleural effusion specimens were prepared with split samples for DQ-stained cytospin and Papanicolaou-stained liquid-based TP. Fifteen pleural effusion samples with immunohistologically confirmed malignant mesothelioma and 13 pleural effusion samples of immunohistologically confirmed pulmonary adenocarcinomas were retrieved from our files. Both DQ cytospin- and Papanicolaou-stained TP slides were evaluated for the known cytological features associated with malignant mesothelioma (25 cytological features) and adenocarcinoma (22 cytological features) without knowledge of the original cytological and histological diagnoses. The McNemar test was used to compare these two cytological preparations for both malignant mesothelioma and pulmonary adenocarcinoma. In the malignant mesothelioma group, 4 of 25 cytological features evaluated, bubbly cytoplasm (P = 0.002), vacuolated cytoplasm (P = 0.005), cell-in-cell arrangement (P = 0.007) and irregular nuclear contour (P = 0.083), were seen more frequently in the DQ cytospin preparation, as opposed to only one feature, nuclear size enlargement (P = 0.008), more readily seen using TP. In the pulmonary adenocarcinoma group, only 1 of 22 cytological features evaluated, presence of angulated or indented nuclei (P = 0.025), was seen more frequently in DQ as opposed to two features, presence of two- cell population (P = 0.04) and presence of micropapillary structures (P = 0.1), were seen more readily in TP. All other cytological features evaluated distinguishing mesotheliomas (20 features) and pleural adenocarcinomas (19 features) were seen equally readily in both types of specimen preparation techniques. This study suggests that the liquid-based TP preparation of pleural effusions does not appear to provide additional diagnostic value when compared with the DQ cytospin preparation in the cytological distinction between mesothelioma and adenocarcinoma in pleural effusions. Most cytological features evaluated, 20 of 25 (mesothelioma) and 19 of 22 (adenocarcinoma), can be seen in both preparation techniques.     

Myeloid leukemia in a urine specimen: A case report and review of the literature

Urinary tract cytology has a long history of utilization for the diagnosis and follow‐up of tumors involving the urothelial tract. As expected, the most common tumor encountered in exfoliative urine cytology is urothelial carcinoma. While the sensitivity of urinary tract cytology for the diagnosis of low‐grade urothelial carcinomas is low, its sensitivity and accuracy for high grade urothelial carcinomas is much higher. However, nonurothelial malignancies, such as hematopoietic malignancies, can also be encountered in urine specimens. Leukemic cells in urine can be diagnosed readily by cytological examination in cases where more invasive procedures are difficult to perform. Additionally, cell block sections can be utilized to determine the immunocytochemical profile of the tumor cells to confirm the diagnosis. Herein we report a case of a 75‐year‐old man with a past medical history of acute myeloid leukemia (AML), who presented with congested heart failure and painless macroscopic hematuria. AML relapse was diagnosed. Cytological examination of the urine using a ThinPrep® smear, cytospin preparation, and immunohistochemical stains performed on the cell block sections were examined. Findings were consistent with leukemic cells of myeloid origin in the bladder washing specimen. Diagn. Cytopathol. 2014;42:700–704. © 2013 Wiley Periodicals, Inc.     

The cell block for body cavity fluids: do the results justify the cost?

We reviewed retrospectively reports on cytologic smears and cell blocks from body cavity fluids received in our department over a 12-mo period. In order to evaluate the usefulness of the two modalities independently, all available slides were studied with the reviewers blinded to the original diagnoses, history, and appearances on corresponding cytology/cell block. Of 524 cytology samples, 283 had cell blocks, of which 263 were available for comparative cytologic and histologic review. Twenty-four cases based on the original reports and 22 cases in the review had diagnoses with major discrepancies between the cell block and cytology. On original reports, cytology favored malignancy in 21 cases in which the cell block was benign, with one false suspicious cytology. In three cases, the cell block was suspicious/positive (two false suspicious cell blocks), but cytology was negative/atypical. In the review diagnoses, there were also 21 cases of suspicious/positive cytology (one false suspicious cytology) and negative/atypical cell blocks. In only one case did the cell block favor malignancy when cytology was benign (a false suspicious cell block). Review of Medicare data indicated that the physician's fee charged for these 283 cell blocks would range from about $7,000 to $28,000 to detect one additional malignancy. We conclude that the routine use of cell blocks is not a cost-effective method of detecting malignancy in body cavity fluids. We advise that samples be refrigerated or be kept fixed. If immunoperoxidase studies are desired following cytologic evaluation, they may be performed subsequently on fresh smears or a cell block.